1. Field of the Invention
The present invention relates to a stapler, and more particularly to a stapler that has a leg-flatting device to bend legs of a staple flatly.
2. Description of Related Art
A conventional stapler has a leg-bending device to bend legs of a staple. However, the conventional leg-bending device bends legs of staple curved, such that the thickness of documents combined by staples is thick. The bent curved legs cannot hold documents with a large thickness and are easily deformed to injure a person. Therefore, staplers with a leg-flatting device such as Taiwan Patent No. I229026 or I1274637 are provided to solve the aforementioned problems.
The '026 Patent disclosed a leg-flatting device with a V-shaped driving element. The driving element has one end connected pivotally to a front end of a trigger lever to driving the leg-flatting device when the trigger lever is pressed. However, the driving element is connected to the front end of the trigger lever, a large force is needed to operate the stapler. In addition, the structure of the conventional stapler is complicated, the cost for manufacturing the conventional stapler is high. Furthermore, to refill staples into the conventional stapler, the trigger lever shall be pivoted to a large angle to open a staple magazine, but this easily causes the stapler turning over.
The '637 Patent disclosed stapler with a sliding element connected between a trigger lever and a leg-flatting device. When the trigger lever is moved downward, the sliding element will be moved to actuate the leg-flatting device to clinch legs of a release staple. However, the sliding element of the conventional staple has complicated structure, to manufacture and assemble the conventional stapler is trouble and time-consuming. Additionally, the force applied to the trigger lever cannot be efficiently transmitted to the leg-flatting device through the sliding element.
Another conventional stapler disclosed in Taiwan Utility Model No. 299629. The '629 Utility Model disclosed a driving device in a lever system form to connect a trigger lever and provide a labor-saving effect. However, the driving device of the '629 Utility Model also has a complicated structure, and the cost for manufacturing the conventional stapler is also high. In addition, the trigger lever shall be pivoted to a large angle to open a staple magazine for refilling staples, and this easily causes the stapler turning over.
To overcome the shortcomings, the present invention tends to provide a stapler to mitigate or obviate the aforementioned problems.